1. Field
One embodiment of the invention relates to a video display apparatus having a super-resolution function, and a video display method.
2. Description of the Related Art
In recent years, the opportunity to view video content using personal computer displays having resolutions exceeding standard definition (SD) is increasing. Also, since high-definition (HD) television broadcasting has begun full rollout, television receivers compatible with the HD standard are becoming common in homes.
Compared to video display apparatuses with such high resolutions, video data captured by image pick-up devices such as video cameras, television broadcast data compatible with the SD standard, DVD, and the like have low resolutions. For this reason, such video data need to be converted into high-resolution data by an arbitrary method. Also, upon displaying a part of a video picture in an enlarged scale or upon picking-up an image by a video camera using digital zooming beyond optical zooming, high-resolution conversion is needed.
Conventionally, in order to achieve such high-resolution conversion, linear interpolation or interpolation based on cubic convolution is used, but such method suffers a problem of insufficient sharpness. To solve this problem, the studies of a super-resolution technique for generating an image that exceeds an original resolution of an image by generating new pixel value data between neighboring pixels to create high frequency components and by sharpening the image have been made. Also, development for embedding a super-resolution function in the aforementioned video input and output devices has been made. Therefore, prevalence of video display apparatuses, video playback apparatuses, and the like having the super-resolution function are expected in the future.
Jpn. Pat. Appln. KOKAI Publication No. 2007-179707 discloses a video/audio playback system which is configured by combining a TV, AV amplifier, DVD player, and the like, and automatically sets the devices that configure the system in optimal operation states in accordance with the presence/absence of video and audio signals and the format of contents recorded in an optical disc to be played back. The user can view the contents in an optimal state by only playing back the optical disc without any special instructions.
However, the video/audio playback system disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2007-179707 controls the devices that configure the system based on the format of contents, but it does not control the respective devices based on functions of the respective devices. For this reason, when both the video display apparatus and video playback apparatus have the aforementioned super-resolution function, super-resolution conversion processing having a sharpening effect is doubly applied to a video picture to be played back. In this case, deterioration of video quality due to noise and over-emphasis of edges may occur.
In order to prevent such deterioration, the control that allows only one of the video display apparatus and video playback apparatus to execute the super-resolution conversion processing has to be made.